27 April 1995 Method for qualitative determination of measurement errors caused by sample fluorescence
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Abstract
Many of the papers and inks used to produce color hard copy products contain fluorescent materials. Most density and/or color instruments use the ratio of value of the light returned by the sample at each wavelength relative to that returned by a white calibration standard to derive the measurement value. Generally, no effort is made to differentiate between light reflected by the sample and light emitted by the sample due to fluorescence. The blue emitted light resulting from the inclusion of fluorescent whitening agents (FWA) in graphic arts materials is excited by violet and ultraviolet (UV) light in the instrument illumination source. Differences in instrument source UV intensity can cause significant differences in the blue reflectance values of FWA containing samples reported by the instrument measurement system. Standard reference materials (SRM) which contain known amounts of FWA are commercially available. These SRMs allow a semiquantitative assessment of the UV content of an instrument's illuminating source. A further refinement, using thin UV cutoff filters, allows the qualitative determination of the presence or absence of FWA in paper samples. We anticipate that with the use of other thin filters, measurement errors caused by visible light excited fluorescence of inks, particular yellows, will be possible.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David L. Spooner, "Method for qualitative determination of measurement errors caused by sample fluorescence", Proc. SPIE 2413, Color Hard Copy and Graphic Arts IV, (27 April 1995); doi: 10.1117/12.207589; https://doi.org/10.1117/12.207589
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